Improvement in piano-fortes



UNITED STATES PATENT OrrrcE.

STEPHEN P. BROOKS, OF BOSTON, MASSACHUSE'FFS.

IMPROVEMENT IN PIANO-FORTES.

Specification forming part of Letters Patent No. l @,673. dated November 2i, i857'.

T0 @ZZ whom t may concern.-

Be it known that I, STEPHEN P. BROOKS, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Piano-Fortes; and I do hereby declare that the nature of the same and the manner in which they are to be performed orare constructed and operated are described and represented in the following statement or specification and the accompanying drawings, of which- Figure l denotes a front eleva-tion of such parts of a pianoforte as exhibit my invention. Fig. 2 is a vertical and transverse section of the same, showing the action or mechanism used for sounding a string.

rIhe nature of my invention consists, first, in combining` and arranging the damper and hammer ot each key ofthe action in one bent lever operated by a tiy or lifter, as will be here inattcr described, and, second, in a peculiar arrangement of the iiy-lifter and escapement or mechanism extending between the jack and hammer.

In the drawings, A denotes the iron or metallic frame; B, the sounding-board; O, the case or wooden frame, D D, the strings; E, the hammer, and F the damper, these latter two being shown as operating on two strings or two branches ot one string in the usual manner. The hammer-head and damper are arranged so that one projects from the other, and both work or turn on one common fulcrum (t, they forming together a bent lever having a hammer-head b fixed to one arm and a damper-cushion c attached to the other arm. A litter K, attached to and projecting from a fly L, is hinged or jointed at one end to the damper-arm, while at its other end it works with the escapement d ot a jack G, projecting upward from the keyll. In the drawings this lifter is represented as forming one piece with the iy, and as bent or extended over the j ack and down upon the escapement, the back catch being shown at c as placed just in rear of the escapement, so that imme-l diately after the fly-lifter has fallen ott the escapement it may be received and rest on the back catch, which operates to arrest the rearward motion ot the hammer until the iinger of the player is raised so as to permit the key to rise upward.

From the above it will be seen that the iiy and lifter are attached firmly together, or are in one piece or bar, and the escapement is arranged on the jack, a regulating-screw and stop or button being applied to the fly and made to work against the jack, as shown at f. One or more spiral springs 3 s extend from the iiy-lifter to the jack and serve to bring' the lifter or liy back on the eseapement when the key is being elevated. Such enables me to construct a very simple and efficient action.

The iron or metallic trame A is fastened to the case O, the sounding-board B (having the bridge l glued to it) being separate from the ease and not directly attached to it, but secured or fastened immediately to the back of the metallic frame. Therefore itis not controlled or strained by the ease under the changes of temperature to which the latter mayT be subjected. Being fastened directly and wholly to the metallic frame, the sonoro us qualityot1 the sounding-board is more uniform, or not so likely to be injuriously affected by atmospheric changes as when the soundingboard is directly connected with the case.

The iron trame is for an upright piano, and it is made square or arched at its top and extends down to the bottom ot the case and rests thereon. It is constructed with a curved hitch-pin plate or bar a?, running from its top down to one of its sides and connected with the bottom plate h2 by two bars c2 (Z2, cast in one piece with the hitch-pin plate and the rest of the frame, and arranged as shown in Fig. l, suoli bars not only extending from the bottom plate h:2 to the hitch-pin plate u?, but along on their outer surfaces and above the same sufficiently to prevent such plates from being warped or twisted under the strain ot the strings. This construction of the frame renders it very strong' and enables the soundboard to be extended beyond the plate c?, as shown in the drawings. It also enables the bridge to be disposed in the middle of the sounding-board, whereby the vibration ot the said board is most etlectually attained.

Having thus explained my invention, what I claim is as follows:

l. Combining' or arranging the hammer and 3. The above-described arrangement of the damper of each string'in or on one bent lever, back catch-viz., on Jhe jack and in rear of substantially as specified. the esoapement.

2. Jointing or hinging the Hyor fly-lifter to In testimony whereof I have hereunto set the hammer-lever and arranging the eseapemy signature. ment on the jack, substantially as described, S. P. BROOKS.

the same dispensing with hing-ing the y to Witnesses: the jack and enabling the fly and lifter to be R. H. EDDY, M made or united in one rigid bar or piece. l F. P. HALE, Jr. 

